Archimedes Plutonium wrote in message ...
I am questioning an assumption. I assume that all shoots emanating from
a grafted tree of its original rootstock is to be pruned off and
suppressed so that the graft becomes the sole plant above ground. Is
that assumption in error? Or can a tree be allowed to express itself
without the graft being exclusive expression above ground?

I wonder if there is an advantage to not cutting off all rootstock
shoots.

The problem with leaving the shoots from the rootstock (called suckers
or watersprouts) in place is that the plant will devote some of its
available energy to these rather than to the valuable top growth.

The rootstock in grafted plants is chosen to resist disease and to
support the top growth (also, particularly in the case of dwarfing
rootstock, to regulate it), not because it has any other value.

Plants on which suckers or watersprouts are allowed to persist will
produce less vegetative growth, flowers, or fruit on the top growth;
if persistently neglected, the top growth may languish, die back, or
even be lost to disease. This is particularly so with the dwarfing
rootstocks commonly used for fruit trees.

--
Chris Green